Electric heater



Dec. 19, 1922.

. T. A. LEWIS ET AL.

ELECTRIC HEATER.

2 SHEETSSHEEI I.

'mcu v1.20. I920.

Dec. 19, 1922 1,439.524. T. A. LEWIS ET'AL. ELECTRIC HEATER. FILED MAR. 20. 1920. 2 SHEETS-SHEEI 2.

I numb LS w CZ, 1 W

Ea ng), @Hozmew W @hyflu wg Patentiid Dec; 19, 1922.

UNITED "STATES, PATENT OFFICE. I

'rnoma A. mrwm .u mmm 1.. mmam, or new roux, n. Y., AssroNons 'ro ammoannmmc COMPANY, A COBI'OBATION or New Yoax.

ELEo'rRrc HEATER.

Application flled larch 20, 1929. Serial Ro. 367,538.

To all whom it may concern:

'Be it known that we, THOMAS A. Lawns an ARTHUR L. Dusnur. (-itizens of the U d States, and residents of New"'York city, New York, the former of Xcw" York County and the latter of Richmond (,duuty,

in said city and State, have invented a new;

and useful Im rovement in Electric Heaters, of which the allowing is a' Specification."

Our invention reliitefito electric heaters. It has for its object to provide a new 'und improved heating element for electrichcaters, capable of withstandiughigh heat, chi-up and e ofconstruction, easily removable and rep ceable, efficient and durable in operation, and one capable of being used with Safety where inflammable gaseea'rc present. It mists of the new and im proved electric hes r hereinafter described.

In electrical heating devices heretofore employed impractical use the heating ele- 'ment 1S exposed to the atmosphere, and accordingly is liable to corrosion and oxidation, especially where high heat employed.

and it is dangerous to usewhere inflammable gases are apt to be present. The liability to oxidation limits the range of temperature that may practically be employed without rapid destruction of the heating element, neeemitating the keeping of the said element at a lower tem rature than otherwise might be desired. ant of course decreasing: the elliciency. Moreover, the removal of the heating element in such devices requires more work and skill than is possessed by most users of such devices.

()ur invention overcomes all these difli cultics. It provides'a device that can safely be used anywhere; that can be used at exin construction and operation, and lIl'WhlCh theheating element can be removed and replaced by anyone.

In the drawings accompanying this specification we have shown our improvement as embodied in an ordinary reflector heater. It is to be understood. of course, that our invention can be employed in any suitable kind of electric heater. The drawings refor red to include Fig. 1, a face view of our improved device in its preferred form and Fig. 2 a vertical cross-section of Fig. 1 on the lines 22 of Fig. 1 viewed as shown by the arrows.

Referring now to the 'drawings, 1 is the stand of the reflector electric heater, 2 the upand 5'conright, and flth reflector part. 4 stltute the u'sual wrire ua rds for such a reflector. BB'flld preferabl filled with an inert gxis such'ai; nitrogen: t is preferubly made of avitmm material of high heat 'rcsistancef. 7 is the usual socket proyidcd'on its inner part with s'crew-threadasas shown;

8 is th support for'thc bulb 6 made in ahy' Suitable way and flecllred'to the bulb in any.

- suitable manner. 9 is'a core of insulating material such as porcelain or a refraotorite composition, upon which is wound the heating element 10. ,11 and 12 are wires leading 'fromithe ends ofthe heating element These and the cable, are connected in the manner usual in lamp sockets, The support 8 of bulb 6 is screw-tin .-.ded on 'the outer side of its projecting part and is uduptedto tit into the screw threads of-sorket 7 so that the bulb can be easily screwed in or removed like an ordinary incandescent lamp. The reflector 3 is provided with a. ring 2; rounected by u spidcrlil to socket Z to hold tinsockct in place in the reflector, This ("onetruction permitgs air to pues betu-m-n the i 'spokes of the spider.

lVeprefer to fill the bulb 6 with an inert gas such as nitrogen, as this helps to conduct the heat from the heating element, and renders the life of the heating element 10 longer and permits it to he run at a very high temperature, thus; inrrvaeingflie elii money of the heater t'thoutdeterioration found it advantageous to uhfrosted glass.

Any suitable material may be used for the heating element, but we preter t/o use a metallic conductor of high heafl and electrical resistance, as thereby our invention can be utilized to its fullest advantage. For '0.\' ample, we may employ any of the well known metals or metallic alloys possessing these roperties. By our improvement very high eats can be maintained, and our device is accordingly useful for many rposes to which the ordinary electric l ter is wholly unsuited. When a bulb is burned -out it can easily be removed and replaced by anyone, and this case of removal and replacement permits the heating element to be run at a much higher temperature than would otherwise be advisable.

I estruetion of the .hcatingelement. .lVherelhe bulb is made of glass we have' \\'e have. found in practice that the use of the enclosing bulb causes a much more even distribution of the heat and minimizes to a considerable extent the deleterious efi'ects of air currents around the heating element. Where the heating element is exposed to the atmosphere difl'ernt parts of theheating element are apt to be heated to different intensities, and the air currents are irregular and uneven. Moreover the air comes direptly into contact with the highly heated parts of the heating element, tending to increase the intensity of air currents and to causethe'm to vary so that much heat is carried upward and away from the reflector and is wasted. With our enclosing bulb the heat from the'heating element as it passes through the gas in the bulb becomes more evenly distributed and more evenly ergualined by the time it reaches the surface 0 the' bulb, and. moreover, the heat at any particular point on the exterior surface of the l)! .b is lower than on the heating element. Tl1ese,difl'erences tend to reduce the intensity of the air currents and cause them, and the heat rays, to be more evenly distributed, and more of them are carried to and discharged from the reflector. We have found in the use of heaters similar to theone illustrated in the drawin 's, that agreat saving of heat is eflected, an that the same results can he obtained with our improved device by the use of from a quarter to a third less wattage than is required in electric devices heretofore used. We have also found that ustill greater saving is effected by'the use of non-transparent glass for the bulb such as frosted or translucent or opaque or colored glass.

What we claim as new and desire to secure by Letters Patent, is:

1. The combination in a' reflector type of heater, of a metallic electrical heating element of high electric and heat resistivity, an insulating and refractory support upon which the heating element is wound, and a,v

sealed bulb enclosing the heating element.

2. The combination in a reflector type of heater, of a metallic electrical l1eati ngelement of high electric and-heat resistivity,

an insulating and ref-ractory'support n which the beating elemont isgoundla remova names to this 5 ment of highelectric and heat resistivity, an

insulatin and refracto su rt u on which thgheatin elementfiis W051i :1 sedled non-transparent liulb mounted on saul supportand enclosing the heating element, the support, bulb and heating element being removable and replaceable as a unit in the heater.

5. The combination in a reflector type of heater, of a metallic electrical heating element of high electric and heat resistivity, an insulating and refractory support upon which the heating element is wound, and a sealed bulb containing an inert gas enclosing the heating element.

6. The combination in a reflector type of heater, of a metallic electrical heatin element of high electric and heat resistivity,

an insulating and refractory support upon which the heating element is wound, a sealed bulb containing an inert gas mounted on said support and enclosing the heating element, the sup rt, bulb and heating element being bib and replaceable as a unit in the heater! 7. The combination in a reflectortype of heater, of a metallic electrical heating element of high electric and heat resistivity, an insulating and refractory support upon which the heati element is wound, asealed non-transpareni fiulb containing an inert gas mounted on said support and anglpsin the heating element, the support, bulb and eat ing element bein removable and replaceable as a unit in the eater.

In testimony whereof, we have signed our:

ification. r HOMAS A. LEWIS. ARTHUR L. DUNHAM. 

